144 REPORT—1845. 
the pressure of the blast, as soon as proper data are furnished bg continued 
inquiries in this field of research. 
The great accordance between the results of the two series of experiments 
now detailed, executed as they were quite independently of each other, the 
one series in Germany, the other in Norway, renders it surprising that a similar 
inquiry instituted by Ebelmen on the furnaces of Clerval and Audincourt 
should have led to results differing so essentially from those now described. 
This chemist gives the following composition, according to volume, for the 
gases of the furnace at Clerval :— 
Height above the tuyére ...|253 feet.) 223. 173. 133. 93. 8. 
DRTOGEN cee. ches cds Ssiocesee 63-07 
Carbonic acid 0-00 
Carbonic oxide 35°01 
Light carburetted hydrogen 0-00 0-00 0-00 0-00 0-00 0:00 
FLYdrogen. ..5....0cccccsscennse 5°82 6-00 5°44 3°82 3°59 1:92 
100-00 | 100-00 | 100°00 | 100-00 | 100-00 | 100-00 
The difference of these results from those detailed above is very striking, 
especially when we consider that carburetted hydrogen is entirely absent 
from Ebelmen’s analyses, and that the hydrogen is as great as 6 per cent. 
The close relation between the nitrogen and oxygen of these gases, and 
especially the great regularity in the increase and diminution of their respec- 
tive constituents, would certainly appear to be a guarantee for the accuracy 
of the analyses. Indeed Ebelmen himself seems so deeply impressed with 
their value and with their exclusive accuracy, that he has considered it quite 
unnecessary even to refer to the previous elaborate investigations on this 
subject in Germany. As he has not honoured one of us, the author of these 
investigations, with a reference, of course the difference between his results 
and those of that paper still remain unexplained, and we shall therefore en- 
deavour to fill up this gap in our knowledge. 
The analyses of Ebelmen differ from our own in being quite destitute of 
earburetted hydrogen. It would be a great error to suppose that the absence 
of this ingredient is not essential. The gas escaping from the furnace at 
Baerum contains, according to weight,— 
Nitrogen . . 2» + » « 5895 
Carbonicacid . . . . + 31°68 
Carbonic oxide . . . - « 728 
Carburetted hydrogen. . . 2°00 
Hydrogen. . . ». - - - O09 
— —__—___. 
100:00 
The two parts of carburetted hydrogen contained in this mixture give, 
on combustion, 26938 units * of heat; and no less than 10°76 parts of car- 
bonic oxide would be necessary to generate the same amount. An error of 
2 in the quantity of carburetted hydrogen, with respect to the combustible 
value of the gas, is equivalent to a loss of 10°76 parts of carbonic oxide gas. 
But surely a theoretical conclusion must be of small value when based upon 
an analysis in which there are errors of more than 10 per cent. of the car- 
bonic oxide. It therefore becomes a most important question tc determine 
* Unit of heat is a convenient term to employ in the present report, because it expresses 
a standard amount. The amount of heat necessary to elevate 2°204 Ibs. of water (1 kilo- 
gramme) from 0° Cent. to 1° C., we assume as unity. 
